In completing building construction projects, it is often necessary to install pieces of gypsum wall board or dry wall within the building. When gypsum wall board is installed, holes must frequently be cut in it to accommodate electrical switches and outlets, windows, etc. Consequently, carpenters installing gypsum wall board have had to employ power tools to: (1) drive screws through gypsum wall board and into the frame of the building and (2) cut holes in gypsum wall board for the electrical light switches and outlets, etc. Generally, the tools which have been used for these operations are a power rotary screw gun (e.g., MILWAUKEER.RTM. Screw-Shooter Nos. 6750-1 or 6753-1) for driving the screws into the gypsum wall board and a separate power rotary cutter (e.g., a router with a rotary cutting bit). When not in use, these tools clutter the job site, and their power cables may create safety hazards. Moreover, when a carpenter is using one of the power tools and needs the other, he must walk away from where he is working to retrieve the other power tool. The use of two power tools to install gypsum wall board is thus inefficient, and, therefore, it is desirable to install gypsum wall board with a single power tool.
Adaptors to convert rotary power tools from one function to another function are well known. However, such adaptors generally must be physically clamped to the power tool by insertion and locking engagement with a chuck or by clamping to a drill bit already in a power tool chuck. Examples of such adaptors are disclosed by U.S. Pat. No. 1,785,065 to Aborn, U.S. Pat. No. 2,346,220 to Kienzle et al., U.S. Pat. No. 3,260,289 to Whitten, Jr., U.S. Pat. No. 3,783,955 to Gill, U.S. Pat. No. 4,052,078 to Benimetzki, U.S. Pat. No. 4,082,475 to Kuder, and U.S. Pat. No. 4,312,610 to Burt. Such devices do not, however, convert screw guns to gypsum wall board cutters. Moreover, these devices are unsatisfactory, because significant time and effort is required to clamp and unclamp these devices to and from a rotary power tool. Thus, the devices disclosed by these patents fail to satisfy the need for an adaptor which can be operatively oriented in rapid fashion with respect to a screw gun or other similar rotary power tool.